I have recently noticed a particular user who persists in
- Contributing very low-quality answers, and
- Refusing to typeset his responses correctly.
Regarding the first point, such answers are often likely deemed low-quality because they are very short and consistently lack insight (and this user has a propensity to post multiple short answers on a single question thread), but my reason for posting this question largely concerns point (2).
On several occasions, I have given this user the link to the standard MathJax tutorial. I mentioned that his contributions would be better received should he actually try to learn the standard medium of communication on this site (Note: This user has been a member for almost 3 years, with a spike in recent activity, and has contributed ~80 answers), but he refuses to do so and recently even explicitly stated that he will never learn MathJax. This is a problem.
I see this user's posts being consistently edited by some well-meaning MSE user(s), but I only see this as perpetuating the problem. Low-quality answers are edited and subsequently bump questions to the front page that otherwise should not be there. The whole situation is rather unfortunate, but what is to be done? Keep flagging and closing (the situation concerning this user's questions is not much better) as I have done? I can continue to do this, but I thought it time to post here to see what the MSE community thinks about this. Is there a possibility of an answer ban of some kind? Etc.